Telephone.



W. U. LOCKWOOD.

TELEPHONE. APPLIGATION FILED JAN. 29, 1909. RENEWED LAPR. 22, 1916.

989,856; I Patentd Apr. 18,1911.

ATTOHNEVJ STA ES .t

' EBHGN specifigatiqn or'g-Iiettersratenfi tenjggfl 1911.

Application filed January a9, 1909, Serial No. 475,078. .mne aepruea; 151a fiefiisl'ilej 551,071.!

To all whom it may concemi Be" it known that I, W Ii KM,

, e' n o mannerisms, 'r'sidi ing at San Juan, in" the Island-1 of Porto; Rico, have invented certain new and-useful Improvements in Telephones,of which the iollowin'g is a specification, reference b'ei'n'g had therein to the accompanying drawing,

' which represents :11 diagrammatic view of one end of atelephone-circuit, showing the transmitter, receiver, andthe localbatteries;

' The mainiobject of this invention is toprovide means for. sendin .a magnetic induced current as wellasa purelyelectriinduced u ent over the Basia-re.

' spouse to vibrations in the transmitter diathrough the other of said double windings, theline being connected to the secondary the transmitter and R the receiver.

' tery.

. winding. 25

Other objects of the invention willappear hereinafter;

Referr ng to the drawing, T designates L designates the. line; T-B the trans mitter battery';-and the receiver bat- The transmitter may of any-desired form, but .I have shown' t constructed substantially in "accordance'with Patent No..

"557,588fiiated April 7 ,1896, grantedto N;

.10; and J5.-

Lockwood. llheftrminals 1 and 2 of the transmitter circuit lead, to the -local' .transmitter battery through the primary. coils of an induction coil 4 mounted in. the receiver. In all ,otherrespects'the transmitter may be of anyordinary and desirable construction. The transmitter cir- 'cuit' is normally open, impulses of current or variations of currentbeing-sent through it by; reason of the vibration of the trans mitter diaphragm The receiver consists of the central in-'- duction coil Lhavihg' the single secondary winding 3,,and a double primary winding 5 and 6. Adjacent the poles of. the core of vthe inductionicoil 4 are arranged electro I magnets 7, said magnets being axially in line with said core. The poles of the-magnets are arranged close to the ends of the .core of.the' induction coil,'as shown in the 7 irectly copnected to coil-'6 and to 66a] "*receivenibafiery: in a closed-min cha e that a constant curreljtt ismaintained mary coil 7 6 One oigthe eledtromagnets is arranged with one; poles adjacent the througlr'the magnets 7 and through the pri-i receiver; diaphragm. lThe transmitter batft ery circuit is j-"colinect'ed to" the primary -,w1nd1n'g 5.; The-main Line- ;wires are con- ---nected to the secondary winding of the in duction coil, Thecoils of the magnet v7 and the primary winding 6; are connected to the transmitter battery whereby the variations the transmitter current will vary 'the"cur-' rent in thegmagnet s7, and in both primary windings; Becaus eiof the closed' local cir- Lguit through the coils of'the'magnet 7 and ethrou gn the primary ,windings 6 of an induction coil the self 'inductance of these coils will .be overcome and the variatioirof 7 current through saidcoils, or the impulses bfcurrent sent through them because of the vibrations of the transmitter diaphragm, 1will instantly set up induced currents, in the me. Itis obvious that therefwillnot be the drag'inthe induced current in this form of *apparatus as. there would be if'there were no closed local circuit through the coils of the induction coil- It will als beob'served that I securelhy means of the magnet 7 an netic force of, the magnets 7 and thereby correspondingly vibratefthe receiver dia- Having thus described my invention, what =ters Patent is mitter, a circuit therefor, a receiverprovided with an inductioncoil having fa double primary winding and a single secondarywinding, an electromagnet adj'acent' each end of induction coil through themagnet coils, the

drawing, The coils of the'magnets aredimagnet coils and H the connected "primary the magnet? and thexprimary windingt of I claim as new and desire to secure by Let-- 1. A telephone 'system comprising transthe core of said induction coil,' -;a fclosed. local fcircuit connected to the coils of the magnets f and to one of the primary windings of the inducedmagnetio current in the line ,as

of the'line they will vary-the.electror'uag- 45 other primary winding of the induction coil,

' line wires connected to the secondary Wll'lClceiver provided with an induction coilhav net adjacent each end of the core of said induction coil, one of the primary windings of ing of the induction coil.

, transmitter, a transmitter circuit connected 'mitter circuit, thesecOnd primary windin of the induction coil-being also connecte ting connected to the secondary winding of the induction coil.

Qcuit, the line being connected to the secondinduction coil having a -.double primary U riably energizing the electromagnets. 6.v .A telephone system comprislnga trans- 1 winding being also connected to the trans.-

with the transmittercircuit, the line wire be- -2..A. telephone system comprising a rethe induction coil being connected to the transmitter circuit and the coils of the'electromagnets being also in the transmitter cirary winding of the induction coil, and a local circuit connected to the other primary wind- 4. A telephone circuit provided with an winding and a single secondary winding, means for maintaining a closed local circuit through one of the, prlmary wmdmgs, a

to the other primary winding, and line wires connected to the secondary winding of the induction coil.

5. A telephone system comprising a transmitter, a circuit therefor, an induction coil having a double primary winding and a single secondary Winding, an electromagnet adjacent each end of the core of said induction coil, one of the primary windings of the induction coil being connected tothe transmitter circuit, a local circuit connected to the ing of the induction coil, and means for vaesaasc 'mitter, a circuittherefor, an induction coil having a double primary winding and a single secondary winding, an elect-romagnet adjacenteach end of the core of said induc-- tion coil,oneofthe primary windings of the inductioncoil being connected to the transmitter circuit, a local circuit connected to the other primary winding of the induction 1 coil, line wires connected to the secondary winding of the induction coil, and means for energizing the electromagnets.

7. -A telephone system comprlsing a transmitter, a circuit therefor, an induction coil formed with a primary winding and a secondary winding, an electromagnet adjacent each end of the core of said induct-ion coil, the primary winding of the induction coil being connected to the transmitter circuit and the coils of the electromagnets being also in the transmitter'circuit, the line being con-t nected to the secondary winding of the induction coil.

8. A telephone system comprising a trans mitter, a circuit therefor, an induction coil, an electromagnet adjacent each end of the core of said induction coil, the primary winding of the induction coil beingconnected to the transmitter circuit, line wires connected to the secondary winding of the induction coil, and means for variably energizing the electromagnets. 9. A telephone circuit provided with an induction coil having a double primary winding and a single secondary winding, an electromagnet adjacent each end of the core of. said induction coil, the windings of the said electromagnets being connected to one of the primary windings of the induction coil and the other primary winding of said coil being in the transmitter circuit, the sec ondary winding of the said induction coil being connected to the line. A

In testimony whereof I hereunto afiix my signature in the presence of two witnesses thisfith day of January 1909.

WM. C. LOCKW'OOD,

Vitnesses:

JUAN M. SAINZ, JOHANNES RICHARD. 

